Good luck! You're going back a while with your Eclipse. I used to work in a gun shop in Leeds and from what i can remember, they are fairly easy to work on. The main-spring is under a fair amount of pre-load, so be careful when you release it. If you have the exploded diagram and are ok with a tool kit, you should be fine. The trigger on those (I think, like I said it was a goodly while ago!) is a bit of a pig so if it's not broke, don't fix it! Just give it a good de-grease then some light machine oil. All the best!
Thanks!
I know it's an old gun.
Coincidentally, Leeds is my hometown